Standardization work by the Third Generation Partnership Project, 3GPP, encompasses Radio, Core Network and Service architecture and protocols. Long Term Evolution, LTE, and LTE-Advanced represent current areas of particular focus by the 3GPP, because of the ability of such networks to deliver so-called 4G data rates. LTE networks include a Radio Access Network, RAN, portion referred to as the Evolved Terrestrial Radio Access Network or E-UTRAN, and an associated Core Network, CN, portion referred to as the Evolved Packet Core or EPC.
One may refer to the document 3GPP TS23.002 for an overview of 3GPP network elements, as used in the EPC and in older, legacy CNs. For EPC details in the context of E-UTRAN access, one may refer to 3GPP TS 23.401. Of course, LTE and LTE-Advanced networks are not the only network types capable of delivering high-rate data services, such as movies, video, and media-rich web pages, and other streaming content. For example, the term “Universal Mobile Telecommunications System” or UMTS broadly refers to radio technologies developed by the 3GPP. Wideband Code Division Multiple Access, W-CDMA, was introduced as an aspect of UMTS by the 3GPP in Release 99 and Release 4, where 3GPP “releases” represent overall sets of related technical specifications. W-CDMA High Speed Packet Access, HSPA, services were added to W-CDMA in the downlink as of Release 5, and in the uplink as of Release 6. HSPA provided significant bit rate increases within the context of W-CDMA, enabling a range of new services, including streaming content services.
Broadly, then, a number of different current network types, and further generation networks now under development, make practical the delivery of rich media content via their higher data rates and more sophisticated enforcement of Quality-of-Service, QoS, and/or Service Level Agreements, SLA, for different types of packet data services, and there is particular interest in receiving streaming content via wireless devices. “Streaming content” is content that is consumed while being transferred. For example, if the streaming content is a video file, viewing begins after an initial portion of the file is buffered at a viewing device and continues as the remainder of the file is progressively transferred to the device.
To facilitate the delivery of electronic content, including streaming content, mobile network operators are turning to content caching, where one or more caches within the wireless communication network provide localized storage of content, e.g., broadband movies for on-demand delivery to wireless devices operating within the network. In a non-limiting example, the network operator caches content from one or more Content Delivery Networks or CDNs. A “CDN” may be understood generally as a collection of web servers distributed across multiple locations to more efficiently deliver content like applications, media streams or software to users.
Nonetheless, the inherent difficulties of managing wireless connections over changing reception conditions and mobility-related handovers leaves significant unresolved challenges to address in the goal of achieving seamless, high-quality delivery of streaming content via wireless communication networks. Indeed, the achievable date rate to individual devices in a given wireless communication network varies substantially as a function of numerous variables, including dynamically changing channel conditions. However, for streaming to work, the average data rate to a wireless device operating in the network has to be high enough to at least keep up with the playback rate of the streaming content, at least to the extent that the overall playback time exceeds the size of a playback buffer within the device that is used for buffering incoming streaming content for playback.
The use of playback buffers in this regard will be understood as an attempt to improve the content consumption experience. Typically, the device initiates playback after a sufficient amount of streamed content has been accumulated within its playback buffer. Then, as content is played back from the buffer, the device refills the buffer with additional content as it is received from the network. The buffer therefore reduces playback interruptions. While the disadvantages of a small playback buffer may be readily apparent, it is advantageously recognized herein that potentially significant disadvantages accompany the use of excessively large, static playback buffers.